Insulated electric conductor



' I- 1945- o. A. J. VAN LINET AL ,3

INSULATED ELECTRIC CONDUCTOR Filed April 8, 1941 0. A. J Mil/v l/A/ d flasks??? fliforizea.

Patented Aug. 14, 1945 2,382,275 INSULATED ELECTRIC CONDUCTOR Oswaldus Anthonius J acobus van Lin, Venlo, and Johannes Hoekstra, Eindhoven, Netherlands; vested in the Alien Property Custodian Application April 8, 1941, Serial No. 387,508

In the Netherlands April 11, 1940 2 Claims.

To make use of insulating layers consisting either of rubber hydrochloride or containing rubber hydrochloride as a chief constituent for insulating electric conductors is known.

Such insulating layers which can be easily made by means of the material commercially lmown as Pliotllm' have excellent electric properties; moreover, they are elastic and have a particularly great mechanical strength. Such an insulating layer may be applied in town of an envelope, for instance by wrapping the material, in form of a band, about the conductor and then heating, so the windings stick together.

in spite cl iactthat these insulating layers are also impermeable to water such an insulating layer is oiten lnsulllolent without the intervention oi. othci means oi em loss of the excelelectnlc nionertles upon contact with winter when the disyuntlve decrease to ti oi the value and toe electric resistance drop appreciably.

The present inventioil has for its object to avoid this drawback order tl the nauticular the lmsulatiu ayecs in c uestion may be utilized as much V T I fife this on insulate 2* consisting of hydrochloride or con ling nibbeihydrochloiide chief constituent is, according to invention, coated an amulet-inc layer which entiaely or lolly entirely consists mobs? co aiming than 66% we ht of chlorine. a layer, which can as easily applied the tom of solution of acquer, has the over other layers im ,erineable to water? of very impermeable and to water" possessing excellent electrical oronertiec such breakdown voltage, insulation dielectric losses.

m Pei at low and high temperatures. Such a layer can.

be obtained in known manner by applying it in form of a solution of cellulose lacquer followed by dryin as an alternative this may be effected by making use of a layer of rubber hydrochloride.

Moreover, a greater rigidity and ductility of the however, a on swbacl: arises in the layer of whole of the insulating layer is obtained according to this executional example.

For making the invention better understood it may still be observed that directly coatingthe insulating layer of rubber hydrochloride with the elastic layer having a great mechanical strength stranded conductor consisting of six steel wires i of use mm. in diameter and two copper wires of 0.35 and (9.5 mm. in diameter respecti'vel twice wrapped in opposite sense with a film 3 of rubber hydrochloride (e. g. Pliofllm") hav ng a width oi 2.5 nuns. and a thickness of tilt mm. This envelope is fused together heating for a short time at 110 to lflll" C. and then coated with a layer consisting, for instance, of'ttlt by weight of trlciesylnhos ohatc and t"l% by weight of chlorinated yubber having a high viscosity. This layer may be pcovided in several layers by painting a solution e. g. in Zoom acne by means Of a nozzle followed by drying of the whole layer which is preferably effected by raising the temperature stepwise or continuously during this drying operation. On; to this layer 5 is applied a layer of lacquer consisting, for instance, of 57% by weight of acetylcellulose, 13% by weight oi triphenyl ohosuhate and 3t% by weight of tributylphosohate "which is followed by drying also this layer. that the wire thus insulated may still be covered in a known manner with a flax braiding (not shown) which may coated in known manner with a compound con taining asphalt bitumen (not shown).

The invention is oiparticular importance for weak current conductors destined for non-permanent telephonic and telegraphic connections where use is often made of a, core usually consisting of a plurality of single metal wires, which core has a hightensile strength, for instance of more than kg. /mm. and requires a thin, light and. strong insulating envelope having a high insulation resistance, as can be obtained accordin to the invention.

What we claim in:

1. An insulated electric cable comprising a conductor, an insulating layer surrounding said con ductor and formed mainly of rubber hydrochloride, and an insulating layer covering said first layer and formed mainly of chlorinated rubber containing more than 60% by weight of chlorine.

2. An insulated electric mnductor as claimed in claim 1, comprising in addition a third insulating layer which is elastic and has a. great mechanical strength at low and high temperatures, "for instance, consisting oi cellulose lacquer. OSWALDUS ANT'HONIUS JACOBUB win LIN. JOHANNES HOEKS'IRA. 

